As conducive to an understanding of the invention it is noted that when a textile web is advanced through a treatment bath, such as a liquid in a tank, by a driven feed roller which advances the web into a ring nozzle which is supplied with liquid under pressure to advance the web through a guide tube, if the advance of the web through the treatment liquid should be interrupted while the feed roller is still advancing the web, the latter may wind around the feed roller even at relatively low speed with resultant need for stoppage of the system to eliminate the blockage due to the improper winding of the web around the roller.
The presently known devices for interrupting the rotary movement of a guide roller in case of trouble in the delivery of the textile material have all the disadvantage that at least one layer of the textile material must be wound on the guide roller before the rotary movement can be interrupted, for example, by shutting off the drive of the guide roller.
Textile material which is transported on the delivery side of a guide roller by means of a liquid current, as it is the case, for example, in soft-dyeing machines, can no longer be unwound from the guide roller, due to the tractive force expended by the liquor current in the wound state. Rather the known devices for interrupting the rotary movement of a guide roller also act as a lock pawl, so that a reversal of the direction of rotation of the guide roller is impossible. An automatic continuation of the rotary movement, after regulating the delivery of the textile material by means of the liquid current, is therefore not obtained. Instead, the textile material is usually damaged and can only be treated with great difficulties, for example, in a treatment in a closed apparatus under excess pressure, after this pressure has been relieved, for which it is naturally also necessary to lower first the temperature of the liquid treatment correspondingly. In addition to the complete interruption of the treatment process, opening of the apparatus and manual intervention are absolutely necessary.
The object of the invention is to provide a device for interrupting the rotary movement of a guide roller for textile material in web form which responds at the first sign of trouble in the delivery of the textile material so early that automatic repair of the defect is still ensured, after which the interruption of the rotary movement is eliminated immediately without the necessity of interrupting the treatment process or manual intervention.
According to the invention there is provided on one side of the guide roller a frame secured on a pivoted lever, which encloses the properly running textile material without touching it, the frame being connected to a switch.
In the device according to the invention, the frame enclosing the textile material in a normal run without touching it is so loaded by the textile material, at the slightest accumulation of textile material on the delivery side, which then no longer runs contact-free through the frame, that the lever performs a pivoted movement and actuates the switch to interrupt the rotary movement.
A particularly expedient design of the invention provides that a rod is articulated on the lever or frame, at the free end of which is arranged a permanent magnet opposite the switch designed as a magnetic switch.
The embodiment according to the invention can be used with particular advantage in pressure tanks where the contact-free magnetic switch can be arranged outside the tank, so that no openings are required in the tank for axles, pins, cabes etc., thus eliminating sealing problems. The lever with the frame and the articulated rod can be so arranged inside the tank by a low-friction bearing, for example, by means of an axle mounted on two points, so that the device is maintenance-free and insensitive to contamination by the treatment liquor.
According to another embodiment of the invention, the switch is arranged between a circuit for driving the guide roller or a circuit for actuating a brake. The invention takes into consideration the fact that it suffices for the interruption of the rotary movement of a driven guide roller to interrupt the circuit for driving the guide roller, while it is generally necessary for the rapid interruption of a non-driven roller to influence the circuit for actuating a brake in case of trouble so that the brake acts immediately as soon as the material begins to accumulate.
Finally, in another embodiment of the invention, the lever carries a displaceable weight on the side opposite the frame.
The displaceable weight permits the apparatus to be adjusted to the desired sensitivity for the interruption of the rotary movement and to ensure, on the other hand, that the device restores the rotary movement as soon as the trouble is eliminated, by returning the frame into the starting position, the premanent magnet actuating the magnetic switch at the end of the articulated rod.